Gear-lapping machine



Sept. 18, 1928. 1,684,872

c. H. LOGUE GEAR LAPP I NG MACHINE Filed July 5, 1925 5 Sheets-Sheet 1C. H. LOGUE GEAR LAPPING MACHINE Sept. 18, 1928.

Filed July 5, 1925 3 Sheets-Sheet If? Tzvzss Sept. 18, 1928.

C. H. LOGUE GEAR LAPPI NG MACHINE 3 Sheets-Sheet I/v z/vroR 6, flTTolvys Filed July 5, 1925 W/TA ?aientecl Sept. 1'8 3.928.

ssmcusn, NEW 2033.

iEAB-LAPPING HACHINE.

itgspiicatlon filed July 3,

This invention relates to a method of and apparatus for truing surfacesof gear teeth which have become more or less deformed 1n the process ofhardening or other heat treatment and involves the use of an abrasiveelement and a gear supporting element in combination with means forrolling the gear with one face of one of its teeth against the abrasiveelement and additional means for imparting to one of the elements acompound motion lengthwise and transversely of the axis of the gear forthe purpose of finishm all portions of said surface to the degree 0nicety required for noiseless and efficient operation when placed inrunning mesh with a companion gear for power transmission, it beingunderstood that the surfaces of all the teeth of the gear will besimilarly treated.

The main object is to provide an expeditious, economical and efficientmethod of lapping the gear teeth surfaces to the required accuracy ofform byrendering the operation upon each tooth surface entirelyautomatic. 7

One of the specific objects is to position the abrasive surface of thelap at the proper angle of obliquity of the tooth surface to be operatedupon so as to form a companion abrasive rack against which the gear isadapted to be rolled and at the same time to impart to the abrasive racka rectilinear motion lengthwise of the surface of the teeth andadditional motion transversely of said surface so that the abrasiveelement may act upon all portions of the toothed surface during eachcomplete run-out of said surface due to the rollin motion of the gear.

Another speci 0 object is to provide means for adjusting the abrasivelap to conform to different angles of obliquity of the surfaces of theteeth to be operated upon.

In the drawings:

Figure 1 is a front elevation of a gear lapping machine for carrying outthe objects stated.

Figure 2 is a side elevation of the same machine except that portionsthereof are broken away to show the interior parts.

Figure 3 is an enlarged horizontal sectional view taken in the plane ofline 3-3, Figure 1.

2925. Serial m. 41,298.

Figure 4 is an enlarged transverse detail sectional view of the abrasivetool and its support and operatin means.

Figure 5 is a horizontal sectional view taken in the plane of line 5-5,Figure 2, portions of the frame being broken away and certain parts ofthe clutch shifting mechamsm being shown in section.

Figures 6, 7 and 8 are-diagrammatic views of portions of the grindinglap and gear in different positions during the run-out of one of thetoothed surfaces with the lap and also showing the different movementsof the lap during said run-out together with the eccentrics 1n differentpositions for producmg such movements.

As illustrated this machine comprises a base 1 having an upright bracket2- extendlng upwardly-from its rear portion, the base -lbeing providedon its upper face with forwardl and rearwardly extendng horizontal gui eways -3 for receivmg and supporting a horizontally movablework-supporting carriage 4. The upper bracket -2- is provided on itsfront face with a vertical guide we 5- for receiving and supportin avert1- cally movable carriage 6- whic is provlded on its front face witha curved guide way 7 havin its center at approximately the point 0contact between the abrasive lap and surface of the gear tooth engagedthereby when at thestarting position of the grinding operation.

The guide 7- is adapted to receive and support a segmental frame 8 whichis movable to different angles about the? center of the curvature of theide 7 as may be required to bring the lap to the desired angle ofobliquity to the surface of the gear tooth to be operated upon in amanner hereinafter more fully explained.

The segment 8 is provided on its front face with a dove-tailed uide way9 extending transversely of and above the guldeway 3 at right anglesthereto for receiving and supporting a transversely movabletoolsupporting carriage lO- A ear supporting mandrel 11- is rotatab ymounted or journaled in axially spaced bearings 12- on the carriage 4-and is provided intermediate the bearings with a cylindrical drum -'-13-for receiving two or more steelor equivalent tapes or hands 14 Woundthereon in reverse directions and havin one end attached thereto andtheir opposlte ends attached to relatively fixed members 1'5- on themain supporting frame whereby the rotation of the Any suitable means maybe employed for effecting either one'of these movements but in thepresent instance I have shown suitable means for rotating the mandrel toeffect the longitudinal movement of the carriage and consequent rollingaction of the gear against the abrasive tool, said'means consisting inthis instance of a worm gear segment -16-' .meshing'with a Worm -17which together with the segment 16- are suitably mounted in a gear case-18- which also forms a bearing for the front end of the mandrel 11.

The object of employing the worm and segment drive for the mandrel 11 isto produce a'relatively slowrotation and bodily reciprocation of themandrel relatively to the abrasive tool but it is evident that otherdriving means may be substituted if desired.

The worm -17 is mounted on a suitable shaft -17 which is journaled inthe lower side of the gear case 18 and adjacent portion of the frame-'1- and is operatively connected by beveled gears l9- to a countershaft --20-, the latter being also journaled in suitable hearings on themain frame '-1 as shown more clearly in Figure 5. i

The shaft 20. is connected by beveled gears 21 to a cross shaft -22-which is also journaled in suitable bearings upon the main frame --1,Figure 5, and is provided with axially spaced beveled gears 23- and -23-loose thereon but held against inwardly axial displacement by collars 24and 24-, Figure 5.

A clutch collar 25-- is splined on the shaft 22 between the gears 2 lforaxial movement into and out of engagement with clutch faces on theadjacent ends of said ears. v

A rive shaft -26 is journaled in suit able bearings on the main frame,Figure 5, and has one end provided with a beveled gear -27 meshing withboth of the beveled ars -23 and '23'; the other end ofsaid driving shaftbeing provided with a pulley -28 adapted to be connected to anyavailable source of power for rotating said shaft in one direction andthereby rotating the gears -23- and -'23. in opposite directions byreason of their engagemenzt with the opposite faces of the gear 2 1 Itis now evident that if the clutch collar 25- is shifted into engagementwith one of the gears as -'23- the worm shaft 17- will be driven in onedirection through the medium of the gears -l9 and 21-'and shaft -20' and+22- and that if the clutch is moved into engagement with the other caras 23- the direction of rotation of't e worm shaft -17- will bereversed. a i

This rotation of the worm shaft 17' in reverse directions will cause thegear-supporting mandrel 11- with the gear -athereon to be rotated .firstin one direction and then in the opposite direction through the medium'of the gear segment 16 which is secured to the gear supporting mandreland at the same time the carriage 4 willbe also reciprocatedin reversedirection thereby producing thedesired rolling motion of the gear --a ingrinding'relation through the abrasive tool.

The shifting. of the clutch collar -25 in reverse directions ispreferably automatic and controlled by the movements of the carriage 4and for this purpose is provided a shifting lever -29 pivoted -at 29-'intermediate its ends-and having one end engaged in an annular oove inthe collar 25- and its other on adapted to be engaged by opposed spacedshoulders 30- and 30' mounted on one side of the carriage -4 as showninvFigure 5, one of said shoulders as '30- being. adjustablelongitudinally upon the carriage 4- and is held in place by a clampingscrew -31 The other shoulder -30' is adjustable lengthwise of and uponthe shoulder 30- and-is held in place by clamping screws The object inmaking these shoulders is to permit the shifting of the clutch collarand The tool supportin carriage -10 is provided with a lengt wise andtransverse guide opening 10- in which is fitted for I finished gears maybe, greatly increased for r a given time by producing additional rela-vsliding movement an abrasive tool 32- having a ilat abrasive surface 32-for engagement with the toothed surface of the gear ato be operatedupon, said tool being properly supported in the carriage --1t)- with itsabrasive member 32 at the proper angle of obliquity to the toothedsurface to be finished and constitutes a single tooth rack against whichthe toothed surface .is adapted to roll as the mandrel is reciprotivemovements between the contact surfaces of the gear-tooth and abrasiveelement and for this purpose 'one of the elements,

' in this instance, the abrasive tool is given a compound reciprocalmotion lengthwise and transversely of the axis of the gearsimultaneously with the rollingmovement of said gear against theabrasive face.

Any suitable means may be provided for producing-this compoundreciprocal motion consisting in this instance of a air of beveled gears33. for transmitting motion from the shaft 22- to an upwardly inclinedshaft --34' having its upper end connected by beveled gears 35 to aforwardly and rearwardly extending cross shaft 36 which is journaled insuitable hearings on the u right bracket --2 and segment 8, t portion ofthe shaft 36 between the segment-8 and upright bracket 2 beingpreferably flexible through the medium of universal joints 36' to allowfor the relative adjustment of the segment 8- as may be required to brin'the abrasive tool 32' into proper grin ing relation with the teeth ofthe gear The Shift se is provided with an eccentric 37-- connected b apitman 38- to one end of the sli ing carriage 10- for reciprocating theabrasive tool -32-- lengthwise of and against the surfaces of the teethof thegear 'a as they are successively presented thereto, the length ofthe abrasive tool being at least equal to the length of the stroke ofthe carriage 10- and of greater length than the gear teeth so as tomaintain grinding relation with the latter throughout the longitudinalmovement of the tool from one extreme position to another.

In addition to this longitudinal recipro- 47 is spline catory movementthe abrasive tool is also reciprocated transversely of the gear teethand for this purpose is provided intermediate its ends with a pair ofcircular openings 39-- in which are journaled rotary eccentries 40--,-on the rear ends of separate forwardly projecting parallel shafts 41.

. These shafts a i are journaied in separate rotary eccentric sleeves 42which,

in turn, are journaled in suitable hearings concentric therewith andtherefore eccentric to their respective sleeves 42 and gears A stubshaft'45 is journaled in a suitable beari in the front wall of thecarriage 10- mi way between and parallel with .the shaft 41- to extendforwardly be-'.

tween" the opposite sets of gears'43 and 44'and upon this stub shaft iskeyed or otherwise secured a pair of pinions 43'-- and 44'meshingrespectively withthe gears ,--43 and 44-- for transmitting rotary motionthereto.-

The front end of the stub' shaft eonnected by beveled gears 46 to across shaft -47- which is journaled in suitable bearings on the segment8 diametrically across the front sides of the gears 43:' and 44-- and isconnected by beveled gears 48- to the shaft .36 .for receiving rotarymotion therefrom, the stub 45- and cross shaft 47 be additionallyournaled in a connecting yo e 49-;

The beveled ear 46- "on the shaft thereon for axial movement relativelthereto and for movement therewit ,.thus permitting the sliding movementof the carriage --10- and parts carried thereby len hwise of the. shaft47 without brea in the driving connections between the sha t 36 andeccentries 40- and 42- It will noted from the fore oing description andupon reference to' figures 3 and 4 that the eccentric sleeves-4% re-,volve in their respective bear' about'parallel axes which are in fixed.re ation to the carriage. -10 while the shafts 41- carrying theeccentrics are eccentrically journaled in their respective sleeves -42in arallel relation and'are therefore move bodily about the axes oftheir respective sleeves as the latter are rotated by the pinion 43--through the medium of their corresponding gears ,--43-.

In view of the fact that the shafts ,4lare rotated eccentrically withreference to the bearings for the sleeves the teeth of the gears 44- andpinion 44' are a relatively longer radially than those of the gears .-43and pinion 43' so as to maintain intermeshmg engagement during theeccentricimovement of the gears 44-.

The gears 43' are of substantially the same pitch while the gears 4 1:are of slightly different pitch, the object of which is to avoidrepetitive travel of the contact face of the abrasive tool in the samepath during successive cycles of movementof the carriage and tool andthereby to present different portions of the abrasive face to thetoothed surfaceat each-cycle of move ment of,both the gear and the tool.

' The ob'ect of the two eccentric 'motions of the abrasive tool -32-.about theaxes of the eccentric sleeves -42- and shafts 41- is to cause aprogressively increasing transverse movement of the tool across the faceof the sired perfection of contour but upon the rein. the directionindicated by arrowsturn of the gear to its starting position after the.face of one tooth has been finished the gear may be removed from themandrel and indexed for a similar operation upon the surface of an othertooth, "these operations being repeate until the surfaces of the teethare properly finished;v

As shown diagrammatically in Figures 6,-

7 and 8 the gear,is set or secured upon the -mandrel in astartingposition in Figure 6 with the base of'the'toothed'surface to'be groundin the lane of the abrasive surface -32'-- at which time the centers ofthe shaft +41%, sleeve and eccentric 40-*' will be in vertical alignmentwith the center of the' eccentric 40 between the center of the shaft -41and the center oflthe shaft --42--for imparting a transverse movement tothe tool -32- at the beginning of the run-out of the surface of thetooth againstthe abrasive surface.

Now as the tape drum -13 is moved rotarymotion willbe imparted theretoin tlle ail-ween indic'ated'by arrow-0- through the medium of one of thestraps --.14 thereby roning the vtoothed surface .under treatmentagainstthe abrasive surface 82'-, this movement being continued unthe entiretoothed surface from'base to point is brought into contact with theabrasive surface thereby establishing a complete runl-out of the toothagainst the abrasive too The bodily movement of the drum -13 in thedirection indicated by arrow mito effect this completerun-out is limitedby the action of the shoulder '-30'-'upon the clutch shifting lever f29-which causes the release of the clutch at the end of the run-out andthereby stops the further 'movement of the carriage and drum 13,

carried thereby in that direction and at the. i

same time the reversing of the shifting lever 29 under the momentum ofthe carriage will cause the clutch to engagethe opposite gear as 23 forreversing the mot1on of the carriage to-its starting position therebyreversing the rolling motion of the gear against the abrasive tool untilthe carriage returns to its starting position at which time theother'stop'--30-' will act upon the shifting gear -29' to stop thefurther movement of thexcarriageand drum at the starting point thuscompleting one cycle of operation which maybe repeated upon the sametoothed surface or the gear may be shifted rotarily to bring anothertoothed surface into operative engagement with the.

abrasive tool, it being understoodthat each toothed surface is operatedupon in thesame A manner.

During the run-out of the tooth from its starting position to the limitof its movement in one direction, theairis of-the sleeve 4;2-' willremain at a constant level but'the axis of; the shaft 41 and eccentricwill be graduall changed to different levels as indicated in iguresfi 7and 8 in such unanncnth'at the resultant movement of the abrasive tooltransverselyof the toothed surface will be gradually increased fromminimum a the start; Figure 6, to the maximum at the finishof the runout, Figure 8, while on the return movement of the carriage -.4-- anddrum'13 this transverse 'movement of the abrasive tool will be graduallyreduced from the maximum throw at the limit of the run-out tothe minimumthrow at the return'to the starting position, itbeing understood thatthe eccentric relation of the parts 40-', 41. and -42 will be soadjusted and that their'bperation is'so timed asto complete-one-halfcycle of rotation during the run-out of the gear against the abrasiveelement and the remaining half of the cycleof 'rotationduring the returnof the rolhng contact. of the gear abrasive element.

that the pulley 28 and i shaft -26' is driven continuously throughagainst the its connection with a suitable source of power and that thegear -a' to be finished is set to its startin position shown in Figure 6at which time t e eccentrics 40;, 41" d iao --- l2 in a position toefiect a minimum reciprocatory movement the abrasive element 32transverseiy of the toothed surface to be operated upon.

Under these conditions the clutch 25- will have been shifted to causethe movement the carriage pe drum -l3-- in the direction indicated yarrow m Figures 6, 7 and 8 thereby causing the rotation of the gear inthe direction indicated by arrow n, these movements continuing until thetoothed surface acted upon effects a complete run-out of contact withthe abrasive tool which during this run-out will be reciprocatedprogressively increasing distances transversely of the face of the tooland at the same time will be moved longitudinally r lengthwise of thetoothed surface.

This compound lengthwise and transversely reciprocatory movement of theabrasive element will continue not only during the run-out from thestartin to the finishing positions as shown in Figures 6, 7 and 8 butalso will continue during the reverse rotation of the gear to itsstarting position resultin in a more eflicient and expeditious finishingof the toothed surface than has heretofore been practiced and greatlyincreasin the output of the work for a given perio of time.

What I claim is:

1. In"a gear lapping machine, an abrasive element, a gear supportingelement means for rolling the gear with one face 0 one of its teeth aainst the abrasive element, and means or moving one of said elementslengthwise and transversely of the axis of the gear.

2. In a gear lapping machine, an abrasive element, a gear supportingelement, means for rollin the gear with one face of one of its teet I aainst the abrasive ele ment, and means inc uding a rotary eccentrio forimparting to the abrasive element a eompound ngthwise and transverse 12ction relatively said face. In gear tapping machine, an sive clement, agear supporting element, means for rolling the gear a iimited disiance"'everse directions with one tace of one c its teeth in contact with theabrasive eiement, means for imparting a compound lengthwise andtransverse motion to said abrasive element relatively to said faceduring said roiling motion.

t. in a gear Eapping machine, an abnsive element, a gear eiement andmeans for rolling one element relatively to the other element with oneof the gear tooth surfaces and abrasive element in contact, and meansfor moving one of said elements transversely of the axis of the gearincluding a rotating eccentric and means for synchronizing the rotationof said eccentric with the movement of the movable element.

5. In a gear lapping machine, a worksupporting carriage, a mandreljournaled on the carriage for supporting the gear treated, means forreciprocating the carriage rectilinearly at right angles to the axis ofthe mandrel, means for causing the rotation of the mandrel during saidreciprocatory movement, a tool-supporting carriage, an abrasive elementmounted on the tool-supporting carriage, and o eratively engaged withone of the teeth of t e gear, and means for reciprocating thetool-supporting carriage rectilinearly and at right angles to thedirection of movement of the work-supporting carriage.

6. A gear lapping machine as in claim in which means is provided forreciprocating the abrasive tool relatively to and transversely of thesecond-named carriage.

In witness whereof I have hereunto set my hand this th day of June,1925.

CHARLES H. LOGUE.

